1. Field of the Invention
The invention concerns a compressed gas interrupter comprising two contact assemblies each having at least one wear contact and one of which is mobile along an axis relative to the other which is fixed and in which the wear contact of the fixed contact assembly is in the form of a rod and in the closed position is inserted into the hollow wear contact of the mobile contact assembly which is moved along the axis by an insulative maneuvering rod. The invention further includes a gas compression chamber which in the open position communicates via an insulative nozzle with an expansion chamber, the nozzle being coaxial with the two contact assemblies and fixed to the mobile contact assembly so that in the closed position the wear contact of the fixed contact assembly passes through it.
2. Description of the Prior Art
An interrupter of the above kind, which can be used as a high-voltage or medium-voltage gas-insulated or air-insulated circuit-breaker or isolator, is described in patent application FR-9211588. In this prior art interrupter the compression chamber that in the open position of the interrupter communicates via the neck of the nozzle with the expansion chamber is a constant volume thermal compression chamber. The gas which blows out the arc is compressed by a piston disposed in another compression chamber of variable volume to the rear of the thermal compression chamber relative to the nozzle. The piston compression chamber and the thermal compression chamber communicate with each other via check valves in a wall separating the two chambers. In the above prior art construction it is therefore necessary to delimit two gas compression chambers and to provide valves for communication between the two chambers.
The aim of the invention is to propose a solution to the above problem by simplifying the construction of an interrupter of the above kind, and in particular to reduce the number of parts constituting it.
This object is achieved by an interrupter which includes a compressible variable volume thermal compression chamber.